Water traps are used in plumbing applications to prevent airborne diseases, insects and vermin and/or unwelcome odorous gases emanating from a drain stack or gully to re-enter a building causing health risks. The particular configuration of the water trap causes it to retain or trap a nominal amount of waste water after each occasion the plumbing application has been used, essentially creating a water seal and in so doing preventing the ingress of the aforesaid from a sewerage drainage system into a building.
Typically, water traps in plumbing applications comprise bottle traps or U, S or P shaped traps and are utilized in plumbing applications, such as toilets, sinks, wash-hand basins, bathtubs, showers and urinals. The various plumbing applications are in operative communication with a sewerage drainage system which facilitates the removal of waste in the form of soil and/or grey water (which can include rain water) from a building to a sewerage line of a greater reticulation system leading to a septic tank or a public sewer.
An important aspect to consider when designing water traps is the continued maintenance of the water seal. Depending on the size and configuration of a particular design a water trap can siphon off water resulting in its defective operation. Various measures are known to prevent water traps from siphoning off. These classically include providing a particular shape to the water trap and/or air by-pass, or employing purge valves in attendance to the trap and other air admittance valves and/or providing for venting within drain lines of the reticulation system.
The greater reticulation system is typically kept at a pressure close to or at atmospheric pressure. The flow of waste within the drainage system creates a positive pressure downstream of the flow which needs to be purged to prevent the water seal in the water traps downstream from being pushed back up into the plumbing application and allowing waste to enter the plumbing application from the drainage system, which is mostly undesirable, save for a gully which is placed to receive waste in that manner and in turn prevent same from occurring in those plumbing applications in which it is undesirable. The entering of waste into plumbing applications from the drainage system will result in unhygienic conditions with potentially severe health and safety implications. Upstream of the flow a negative pressure is created which needs to be purged to prevent upstream water traps from being siphoned off. In the event of the water seals being broken, airborne diseases and unwelcome odorous gases will freely be able to pass from within the drainage system into a plumbing application and into the building causing unhealthy and unsavory habitation conditions.
Venting and/or air by-pass pipes known to be used in helping to maintain desired pressure in the drainage system are costly, have been known to draw out water seals by high-velocity winds passing over the top of the stack and become clogged and thus prevent the effective purging of that system resulting in defective drainage of waste. Air admittance valves are also known to be used within drainage systems in order to maintain the desired pressure within that system. Although this venting means assists in the maintenance of a desired operative pressure within the drainage system, such mechanisms provide for additional movable parts in an apparatus assembly which often fail, and may be prone to maintenance and repair procedures escalating cost implications.
Typical existing water traps are prone to blockage owing to retained waste solids obstructing a necessary flow path having several bends and a relatively long confined flow path. There is consequently a need for a water trap design which will assist in the flow of waste or prevent the back flow of waste and which will assist in preventing the water seal being siphoned off under excess negative flow pressure. There is also a need for a water trap wherein the confined flow path is reduced having fewer confined bends facilitating the flushing of waste solids. There is a further need for easier and more convenient access to the water trap, if maintenance is required. Conventional drains also require separate access to the trap for maintenance to be conducted.